The object of the invention is to improve such mounting devices or catches so as to expand their usefulness and make their operation more secure. In particular the present invention addresses the problem of a high in-service failure rate experienced for this type of mounting device.
Mirrors and other glass sheets are heavy, hard, and frequently have sharp rectangular edges. Devices similar to the present invention are commonly used for hanging mirrors and other glass sheets to walls, doors, cabinets and other flat surfaces. This family of hangers are typically made from hard plastics, which are aesthetically pleasing, inexpensive to fabricate and soft and resilient enough to preclude damaging the mirror or glass sheet. For example, U.S. Pat. No. 5,295,651 teaches a plastic mirror mounting clip similar to the present invention, with a slidable mounting configuration. Also, U.S. Pat. No. 4,340,199 teaches a similar hanger having two pieces that are slidably connected.
In-service failures of these types of mounting devices have been experienced whereby the vertical lip and/or horizontal flanges break, allowing the mirror, glass sheet or other flat object to fall with predictable catastrophic results. This failure mode is a result of the weight of the glass impacting the plastic mounting devices. The local forces on the plastic clips may be further magnified during installation by the speed of the vertical movement when placing the glass sheet on the lower clips, and by the relatively sharp edges of glass sheets, which may concentrate the forces on the clip.
Mirrors and other glass sheets are virtually ubiquitous in American homes, and the number of in-service mounting devices therefore number in the hundreds of millions. Therefore any reduction in the failure rate for these devices will have a significant aggregate economic impact. For the foregoing reasons, there is a need for an inexpensive mounting clip with improved strength that will support heavy objects such as mirrors and glass plates without breaking.